Process for the manufacture of paper



Dec. 1, 1936.

A. E. H. A lR PROCESS FOR THE MANUFACTURE OF PAPER 2 SHQQts Sheet 1 Filed March 7, 1934 Dec. 1, 1936. A. E. H. FAIR PROCESS FOR THE MANUFACTURE OF PAPER 2 Sheets-Sheet 2 Filed March 7, 1934 QQ W 21 jZZl/i 7 2.1,

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Patented Dec. 1, 1936 PATENT OFFICE PROCESS FOR THE MANUFACTURE OF PAPER Albert Edward Harold Fair, St. Catharines,

Ontari Application 1 Claim.

My invention relates to a process for the manuiacture of filled paper. Heretofore in the paper making art it has been usual to mix the batter or paper making materials in a vat or, as is commonly known in the art, a beating engine. The ingredients placed in the beating engine have been fibre, the usual chemicals and the filler which, in the practice of the art, has been among others lithophone, calcium carbonate, titanium oxide, barium sulphate and various combinations of zinc sulphide with barium sulphate and combinations of the titanium oxide with barium sulphate. These fillers, as is well-known in the art, are costly and the loss of part thereof adds considerably to the expense of paper making.

The object of myinvention is primarily to obviate the loss of the larger proportion of these fillers which has heretofore been occasioned in the art of paper making.

Heretofore the process has been to dilute the suspension or solution in the flow boxes to about to 1% of fibre chemical and filler to about 99 to 99 water, then to flow through a suitable lip or sluice, this suspension on to the Fourdrinier part, or as is technically known in the art, thewire" of the machine which by revolution, capillary attraction and vacuum gradually reduces the water content, and then by a well-known process the fibre suspension is drawn on to the presses, thence to the driers and so to the calender rolls. It is known in the art that the extraction of the water through the action of the Fourdrinier part results in a large loss of the suspension of fillers and chemicals which, while capable of being reclaimed to some extent, occasions a very considerable loss in reclamation, particularly of the fillers. The fillers, being costly, occasion a wastage which makes an increased cost in the manufacture of filled paper.

The object of myinvention is to obviate the loss of filler in the fibre suspension passing over the Fourdrinier part. A further object of my invention is to provide greater opacityin the filled s paper which I produce, thereby rendering not only a better product but at the same time a product of greater economy to manufacture at a decreased cost.

In accomplishing my invention I mix in the beater engine only the fibre, water and chemical, leaving therefrom the filler. As is well known in the art the batter or fibre suspension is further mixed with a large quantity of water in the fiow boxes from which the suspension is fed on to the Fourdrinier part.

For better understanding of my invention I March i, 1934, Serial No. 714,491 In Canada; June 16, 1933 refer to the drawings hereunto annexed in which Fig. 1 represents one embodiment of my device, Fig. 2 represents a modification of the device shown in Fig. 1.

Referring to Fig. 1, l indicates the flow box in which the batter or fibre suspension is finally mixed before being fed on to the Fourdrinier part or wire 2, which is operated by the usual roll 3, in a suitable manner. 4 is the lip of common construction employed to feed the fibre suspension on to the Fourdrinier part. I now employ a suitable series of sprays 5, fed by means of pipe 6, actuated by pump 1 from vat 8 in which vat 8 is operated an agitator 9 and which vat contains the filler suspension of whichever type I desire to use for the particular paper under construction. It will be seen from the drawing that the spray 5 is directed against the upper surface of the lip 4 which causes the filler to be fed evenly on to the upward surface of the fibre suspension passing over the Fourdrinier part.

It will be understood that the filler, thus being on the surface of the fibre suspension, remains there as it passes over the Fourdrinier part, the water being therefrom extracted without displacing the position of the filler relatively to the fibre suspension.

It will thus be seen that the filler suspension which is fed on to the surface of the fibre suspension as it passes over the Fourdrinier part is not lost in large measure as has heretofore been the case and that reclamation of the filler becomes in a marked degree less important. Thus the loss of filler, heretofore seen occasioned in the art is obviated.

When the fibre suspension, with the filler thereon superimposed, has passed over the Fourdrinier part on to the presses and calender rolls the result accomplished is a filled paper in which the paper filler remains substantially intact upon the upper surface of the paper. Not only is the filler retained without substantial loss but a better result is achieved for some purposes, in that the coating can be retained substantially on the surface of the paper. Due to my process the fibre controls to a large extent the retention of the filler, particularly on the upper surface of the fibre suspension or paper web. In the product made according to my invention the surface is substantially uniform, still retains the opacity required in this type of product, and at the same time makes possible the production of a filled paper by economical means, due to the smaller amount of filler necessary to be used.

While defining my invention as shown in Fig. 1

it will be understood that I do not limit myself to placing the spray nozzles which spray the filler on to the lip and thence to the fibre suspension at the point of entry of the solution on to the Fourdrinier part. In reference to Fig. 2 it will be noticed that spray nozzles I and supply pipe 6 therefor may be moved downward along the Fourdrinier part or wire '2. In this, my preferred embodiment of the invention, I provide a shield Ill which is made of sheet metal or other suitable material, preferably having vertical corrugations thereon to assist in the flow of the spray about to be described. The shield I is provided with a resilient lip II which is adapted to feed at its point of contact with the surface of the fibre. suspensions as it passes over the Fourdrinier. I provide a suitable number of sprays 5 fed by means of pipe 6 actuated by pump 1 from vat 8 in which vat 8 is operated an agitator 9 and which vat contains the filler suspension of whichever type I desire to use for the particular paper under construction.

The filler suspension fed by the sprays 5 being directed against the shield l0 flows down the surface of the shield III which is inclined at an angle of suitable proportions to enable an even fiow on to the lip i I. The lip II is preferably of resilient material which will allow the filler suspension to be flowed on to the fibre suspension in an even manner. While the spray nozzles 5 may be so adapted either to throw a circular or other shaped spray I find that a fan shaped spray produces the best results. The resilient lip H is preferably of rubber and by reason of its resting as nearly accurately as possible on the surface of the suspension fluid as it flows over the Fourdrinier part the impact of the filler in the spray is prevented from falling directly on to the fibre suspension. The primary object of the resilient rubber lip is to prevent the formation of drops or globules, and the use of the corrugated shield provides an even distribution and flow of the filler suspension,

. thereby preventing the formation of streams of filler along the Fourdrinier part which has the result of producing paper with marks or blotches.

The shield l0 and spray nozzles 5 are adapted to be movable along the Fourdrinier part so that the filler suspension may be flown on to the fibre aoeases suspension at any suitable position required. In general use I find that its location about five feet from the lip of the flow box I produces paper of good quality, but the position will vary according to the weight of paper required. If a heavyweight paper is desired the spray nozzles with the accompanying shield and lip should be placed fairly close to the point at which the fibre suspension is fiown on to the Fourdrinier. Where a lighter paper is required the spray nozzles and shield should be placed further down the Fourdrinier part for the reason that the mat of fibre is there more, completely formed and a satisfactory and uniform distribution of filler can thus be obtained by adding the filler suspension farther along the Fourdrinier part.

It will be seen that by the use of my invention I am able to obtain a paper of greater opacity with the use of a minimum of filler and am also able to save large quantities of expensive fillers which have heretofore been lost in the art of paper making. By having the point at which the filler suspension is fiown on to the fibre suspension movable with respect to the Fourdrinier I am able to produce different grades of paper by the use of different quantities of filler, thus producing a better product at less cost than heretofore.

In addition there is an adaptability to make different grades of paper by the use of varying quantities of filler.

It is to be noted that my invention is not to be confined to the manufacture of filled wood fibre paper, but may also be used with equal results in the manufacture of filled paper whether manufactured from wood fibre, rag fibre or any other suitable fibre.

What I claim as my invention is:

The process of adding filler suspension to a fibre suspension on the Fourdrinier of a paper machine consisting in spraying the said filler suspension in a finely divided state against an inclined baflle and thence flowing the same by gravity on to the top of the fibre suspension on the Fourdrinier in such manner as to insure even distribution of filler suspension and the elimination of foam and bubbles in the fibre suspension.

ALBERT EDWARD HAROLD FAIR. 

